iphone - 滚动超过列表的开头或结尾时，UIPickerView 使应用程序崩溃

Question

我是 iOS 开发新手，所以这可能很容易解决。我有一个自定义 View Controller ，我在其中采用协议(protocol)来控制 Nib 中的 UIPickerView。一切正常，除非在 iPad 模拟器中，我将选择器滚动到列表中的第一项或列表中的最后一项之外并释放。它踢出以下错误:

线程1:程序接收信号:“EXC_BAD_ACCESS”

在我的 main.m 类的这一行:

int retVal = UIApplicationMain(argc, argv, nil, nil);

相关代码如下:

View Controller .h

@interface BirdColorViewController : UIViewController <UIPickerViewDelegate, UIPickerViewDataSource> {
IBOutlet UIPickerView *birdColorPicker;
NSArray *birdColors;
}

@property (nonatomic,retain) IBOutlet UIPickerView *birdColorPicker;

View Controller .m

- (void)dealloc
{
[birdColorPicker release];
[super dealloc];
}

...

- (void)viewDidLoad
{
    [super viewDidLoad];
    birdColors = [NSArray arrayWithObjects:@"Blue",@"Yellow",@"Red",nil];

    birdColorPicker.delegate = self;
    birdColorPicker.dataSource = self;
}

...

#pragma mark - UIPickerViewDataSource methods

//(UIPickerView *)thePickerView

- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
{
    return 1;
}

- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component 
{
    return [birdColors count];
}

 #pragma mark - UIPickerViewDelegate methods

- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component 
{
    return [birdColors objectAtIndex:row];
}

- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component 
{
    // Set value in prefs/model
}

Answer 1

尝试:birdColors = [[NSArray alloc] initWithObjects:@"Blue",@"Yellow",@"Red",nil];而不是 birdColors = [NSArray arrayWithObjects:@"Blue",@"Yellow",@"Red",nil];